Apparatus for handling stacked contaziners



Dec. 8, 1964 E. T. HOLLAND, JR 3,160,250

APPARATUS FOR HANDLING STACKED CONTAINERS Filed Feb. 1, 1961 2 Sheets-Sheet 1 EDWARD THOLL/I/VD JR. INVENTOR.

glm ezf ATTORNEY Dec. 8, 1964 E. T. HOLLAND, JR

APPARATUS FOR HANDLING STACKED CONTAINERS 2 Sheets-Sheet 2 Filed Feb. 1, 1961 4 I l I l i I i fowqkaffloLLAA/a JR. INVENTOR.

ATTORNE Y United States Patent 3,160,260 APPARATUS FOR HANDLING STACKED QGNTAHQERS Edward T. Holland, lira, Cedar Rapids, Iowa, assignor to Cherry-Brunei! Corporation, tCedar Rapids, Iowa, a

corporation of Delaware Filed Feb. 1, 1961, Ser. No. 86,445 6 (Ilaims. (Cl. 19835) This invention relates to an apparatus for handling a stack of containers and more particularly to an apparatus for unstacking containers by first laying the stack on its side and then tipping each individual container 90 to either an upright or upside-down position depending upon the purpose for which the apparatus is used.

There are on the market today many machines designed to unstack container-s. Many of these machines are extremely complex and expensive to manufacture, particularly those designed to handle open-top containers carrying fragile items, such as glass bottles, since the containers must be handled in such a way to prevent the contents from falling out during the unstacking operation. There is another type of apparatus on the market designed primarily for use in the fruit packing industry in which the apparatus operates to unstack a stack of crates loaded with fresh fruit and tip each crate upside down to remove its contents. This latter type of upstacker operates on the principle of first laying the stack of containers on its side and then tipping the individual containers to empty their contents. The machines of this type presently known to me are also relatively complex although the principle of operation is somewhat simplier than unsatckers or" the first type which maintain the containers in an upright position at $1 times during the operation.

My invention is directed to an unstacker of the second type which can, however, be used also in most installations where unstackers of the first type are commonly used. It will be seen that I have invented a basic machine that can be easily modified to suit the needs of a particular installation. Thus, my invention relates to a basic apparatus that is extremely versatile thereby enabling it to perform various functions with only slight modifications of structure.

It is therefore a principal object of my invention to pro vide an improved apparatus that is designed for handling and unstacking stacks of containers, such as milk cases.

Another object of my invention is to provide a basic apparatus that with only slight structural modifications can be used either in unstacking containers that must be kept in a somewhat upright position at all times or the apparatus can be used where it is desired to tip the containers over to empty their contents.

It is a further object of my invention to provide an apparatus for handling stcaked containers that is extremely simple in structure and operation and efficient and gentle in its handling of the containers.

It is a still further object of my invention to provide an unstacker that can be easily and inexpensively manufactured.

These and other objects of my invention will be apparent from a consideration of the following description taken in connection with the drawings in which:

FEGURE l is a perspective view of my novel apparatus, showing the stack cradle in a downward position;

FIGURE 2 is a side elevational view of the apparatus showing the stack cradle in an upright position;

FIGURE 3 is a top plan view of the apparatus of FIG- URE 2; and

FlGURE 5 is an enlarged view of a portion of the stack cradle showing certain details of structure.

My novel unstacker is comprised of a pair of conveyor chains '19 that are operated by a common drive unit (not shown) and therefore are driven at the same rate of speed. These carrier chains 10 traverse guide channels 12, the lower surfaces of the chain 10 engaging the floor of the guide channels and the upper surfaces of the chains lit being slightly higher than the top of the guide channels 12 to engage the containers C that are received by the apparatus stacked one on top of the other to form a stack S. The conveyor chains 10 are preferably of the endless type and therefore are returned to the drive unit in the return guide channels 14 at a level below the guide channels 12. The conveyor chains 10 are shown as a part of a conveyor system, but with slight modifications and with the addition of a drive unit the unstacker could be made an independent unit. The guide channels 12 and return channels 14 are supported on suit able framework 16 which has side members 17 that flare slightly outward and provide guides for the containers being carried on chains 10. In the apparatus shown, the framework 16 is supported a distance from the floor by legs 18. However, the unstacker could 'be installed with the conveyor chains It) in the floor in which case a pit would be necessary to house those portions of the apparatus below the floor level.

As best seen in FIGURE 2, the conveyor chains 10 are laterally spaced apart and follow substantially parallel paths. Mounted between the chains 10 is a stack cradle indicated generally by the reference numeral 29. Stack cradle 20 is comprised of a channel-shaped main frame member 22 that is pivotally mounted by being secured rigidly to a shaft 24 turnable in bearings 26 secured to the framework 16. Fixed to the shaft 24 at right angles to the main frame member 22 there is a stack supporting platform 28 of suliicient size to support the containers to be handled. Being secured to the shit 24, the platform 28 pivots with the main frame member 22 as the shaft 24 turns in bearings 26. Both the main frame member 22 and the platform 28 must be narrow enough in Width to permit the cradle 20 to pivot to a horizontal position between the guide channels 12. When the main frame member 22 is in a vertical position the platform 28 is in a horizontal position and at a level slightly below the top surfaces of the conveyor chains it).

Secured to the main frame member 22 and extending in the opposite direction is a pair of rigid arms 35 Interconnecting the ends of these arms 30 and the free end of the stack platform 28 are a pair of curved case stops 32. The case steps 32 are rigidly connected to the arms 30 and platform 28 and pivot with the main frame member 22. as the shaft 24 turns in bearings 26. Therefore, when a stack of cases is carried by the conveyor chains 19 onto the platform 28 and the cradle 26 starts pivoting downwards, the stops 3?. will prevent the next stack of cases from further travel.

Rotation of the stack cradle 29 from a vertical position to a downward position between and slightly below the conveyor chains 10 preferably is accomplished by the use of a double-acting air cylinder 34 that is pivotally mounted at its end on a depending arm 36 of the framework 16. A piston rod 38 extends from the other end of cylinder 34 and the rod 38 has its end pivotally connected to a crank arm 40 that is rigidly fixed to shaft '24 of the stacking cradle 29. The air supply that actuates cylinder 34 preferably is controlled by a four-way, springreturn solenoid valve (not shown) that is operated by a limit switch 42 (FIG. 4). Switch 42 is mounted on the back of the main frame member 22 just above an opening 44 in member 22. A bar 46 is pivotally mounted on the opposite or stack receiving side of the stack cradle 20 on links 48 and St) that are pivotally secured to the main frame member 22. Link 549 is L shaped and extends through opening 44 in the main frame member 22 to engage the trip arm 52, of switch 42 actuating the switch \9- when the bar 46 is depressed. A spring 54 has one end connected to link 50 and the other end secured to the shaft 24. The spring 54-therefore acts through the link 50 to bias the bar 46 to a position away from the frame member 22. In this position, the link 56) maintains contact with the trip arm 52 but does not actuate the switch 42 until the bar 46 is again depressed.

Thus, as a stack of cases is carried by the conveyor chains 16 onto the platform 28 the stack depresses the bar 46 forcing it closer to the main frame member 22. The bar 46 pivots on the links 48 and 50, the latter actuating the switch 42 to energize the solenoid valve and allow air to flow into the cylinder 34. Piston rod 38 of cylinder 34 exerts force on crank arm it) causing the stack cradle 29 to pivot. The cradle 2t continues its rotation until it rests between the chains 14) thereby setting the cases on their sides on the chains 10. The individual cases are then picked up by the chains and moved off the stack cradle 20. When the last case is carried oi the cradle 29, the spring 54 will return the bar 4-5 to its initial position. This disengages the switch 42 thereby opening the circuit to the solenoid valve the nature of which is such that the air pressure will be directed to the other side of the piston in cylinder 34. The piston rod 33 then will be forced to the right (FIG. 3) rotating the stack cradle back to a vertical position.

Having received the cases in an upright position stacked one on top of the other, the cradle 20, when rotated to the horizontal position, will lay the cases on their sides on the conveyor chains 16). In some applications, for example in a dairy plant, it is desirable that the cases when unstacked be returned to an upright position. I have provided a simple means for doing this but first the cases must be separated a sufficient distance to allow them to be tipped. This is accomplished by meansof a rough top endless-belt 56 that travels around two rollers 58 and 6E). The belt 56 is positioned between the chains with its top surface slightly above the top surfaces of the conveyor chains 10. The belt rollers 58 and 60 are mounted on shafts. 62 and 64 respectively. Shaft 62 rotates in bearing 66 and shaft 64 rotates in bearing 68,-

these hearings each being suitably fixed to the framework 16. One end of shaft 64 extends beyond bearing 68 and a sprocket 70 is fixed thereto. The sprocket. 7th is rotatably driven by chain 72 which engages a drive sprocket 74 driven by a motor 76 through speed changer 78. The belt 56 is driven at a rate of speed considerably faster than conveyor chains 10 and therefore as a container is picked up by belt 56 it will be separated from the container following it. Spacing of the containers can. be regulated by varying the speed of the belt 56.

Returning the containers to an upright. position is accomplished by a pair of depending arms 80 that are suspended above belt 56 from a cross bar 82 mounted on two upright supports 84- secured to framework 16. The arms 80 strike the edge of the container holding it back, and as the belt 56 continues to move the container, it will be rotated 90 to an upright position. The method is effective only where the height of the container is less than its width.

Operation of my novel unstacker is as follows:

A stack of containers S will be carried by conveyor chains 10 onto the platform 23 of the stack cradle 20. The force exerted on the stack S by conveyor chains 10 will be sufficient to force the stack against the bar 46 on the stack cradle 20 and actuate switch 42 to operate the air cylinder 34 and thereby rotate the stack cradle 20 downwardly. The stack cradle 20 will, of course, carry with it the stack to a horizontal position and place the containers again on the conveyor chains 10. With the containers now resting on their sides they will be carried by chains 10 onto belt 56 which separates the containers because it is running at a higher speed than conveyor chains 10. As the individual containers on belt 56 pass under the depending arms 80, they will be tipped to anv upright position and discharged by the conveyor belt 56 back onto the conveyor chains 10.

Additional stacks of containers being carried by conveyor chains 10 will be stopped by the case stops 32 at any time when the stack cradle 20 is in a position other than a vertical position. After the last container is carried OK the stack cradle 29, the switch 42 will be disengaged by bar 46 thereby causing the air cylinder $4 to return the stack cradle 24 to an upright position. When the stack cradle 26 has returned to the upright position, it is in position to receive another stack of cases and repeat the operation.

Although my unstacker is shown substantially level, it may be desirable in some applications to have the apparatus constructed on an incline from left to right (FlG. 2). For example, in a dairy plant using glass bottles, the cases are returned filled with empty bottles. A slight incline of about 10 from the horizontal will prevent the bottles from falling out of the cases during the unstacking operation.

In some uses for my novel apparatus it may be necessary to tip the cases upside down after they are unstacked. If so, the conveyor chains it) should be adapted to start their return in guide channels 14 just before the discharge end of belt 55d and the depending arms 8t would be eliminated. Then, another conveyor (not shown) running either parallel or transversely to conveyor chains lit) could be mounted a short distance under the discharge end of the belt 56. Thus, as a case on its side approached the end of belt 5r: it would be carried off and turned upside down on the second conveyor and the desired result would be accomplished.v

It is thus seen that my invention has many applications and with only slight modifications can be used to perit is my intention that such modi'-' form many functions. fications and revisions of the invention as are reasonably expected on the part of those skilled in the art will be included within the scope of the following claims.

I claim:

1. An apparatus for handling stacked containers comprising a first continuously moving conveyor, means for receiving a stack of containers from said first conveyor and laying said containers on their sides on said first conveyor, a second continuously moving conveyor adapted to receive said containers from said first conveyor after they have been laid on their sides by said means, said second conveyor operating at a linear speed higher than said first conveyor whereby the individual containers picked up by said second conveyor from said first con- .veyor are separated from each other, and means toturn the individual containers ninety degrees after they have been separated on said second conveyor.

2. The apparatus of claim 1 in which the means to turn the containers comprises'a rigid depending arm in the path of the individual containers.

3. The apparatus of claim 1 in which the first and second conveyors are inclined.

4. An apparatusfor handling stacked containers comprising supporting means for said apparatus, a continuously running first conveyor having laterally spaced-apart portions running at the same speed, .a stack cradle pivotally mounted on said supporting means between the portions of said conveyor, means to pivot said cradle back and forth between an upright position and a horizontal posit-ion, a continuously running second conveyor located downwardly from said stack cradle and mounted between the portions of said first conveyor with its container engaging surface at a level above the top surfaces of said first conveyor, saidsecond conveyor running at a speed greater than the first conveyor whereby containers carried onto said second conveyor from said first conveyor are separated, and means associated with said second conveyor to overturn the individual containers carried thereon.

5. An apparatus for unstacking containers stacked one 33 on top of the other, said apparatus compnisiag a continuously operating conveyor adapted to carry containers thereon and advance them along a defined path, a stack cradle in the path of the stacked containers being advanced by said conveyor, said cradle being mounted for pivotal movement about a horizontal axis transversely oriented with respect to the direction of movement of said conveyor, said cradle having a frame member and a stack supporting platform substantially at right angles to said frame member, the frame member being normally in an upright position and of a height at least that of the stack of containers to be handled, the pivotal axis of said cradle being located below the container engaging surface of said conveyor so that said frame member will lie below said surface when said cradle is in a downward position, power means to move said stack cradle back and forth from a position in which the frame member is upright to a position with the frame member below the container engaging surface of said conveyor, actuating means for said power means, said actuating means including a movable actuating bar substantially the same length as said frame member mounted on said member in parallel relationship thereto, means to bias said bar away from said frame member, and a switch actuated by movement of said bar toward said uprightmember to actuate said power means and thereby cause said cradle to pivot to a downward position, said cradle remaining in the downward position until said bar is released by the last of said containers being carried ofif by said conveyor.

6. In combination with the apparatus of claim 5, a case stop secured to said stack cradle and movable therewith to prevent containers on the conveyor from further movement when said cradle is in any position other than an upright position.

References Cited in the file of this patent UNITED STATES PATENTS 1,422,057 Hooper July 4, 1922 1,632,204 Threefoot et al June 14, 1927 1,854,446 Campbell Apr. 19, 1932 2,242,532 Marx May 20, 1941 2,498,740 Miller Feb. 28, 1950 2,601,507 Eshelman June 24, 1952 2,664,992 Bahney Ian. 5, 1954 2,786,588 Hill Mar. 26, 1957 2,829,761 Roeber Apr. 8, 1958 2,851,147 Hageline et a1. Sept. 9, 1958 

1. AN APPARATUS FOR HANDLING STACKED CONTAINERS COMPRISING A FIRST CONTINUOUSLY MOVING CONVEYOR, MEANS FOR RECEIVING A STACK OF CONTAINERS FROM SAID FIRST CONVEYOR AND LAYING SAID CONTAINERS ON THEIR SIDES ON SAID FIRST CONVEYOR, A SECOND CONTINUOUSLY MOVING CONVEYOR ADAPTED TO RECEIVE SAID CONTAINERS FROM SAID FIRST CONVEYOR AFTER THEY HAVE BEEN LAID ON THEIR SIDES BY SAID MEANS, SAID SECOND CONVEYOR OPERATING AT A LINEAR SPEED HIGHER THAN SAID FIRST CONVEYOR WHEREBY THE INDIVIDUAL CONTAINERS PICKED UP BY SAID SECOND CONVEYOR FROM SAID FIRST CON- 